Generally described, communications may take place over a variety of channels. Communications channels may include, for example, one-way and one-to-many channels such as television, radio, newspapers, magazines, billboards, paper mail, and other media. Communications channels may also include online and interactive channels, such as email, the web, search engines, social media, instant messaging, audio or video streaming, podcasts, interactive software (e.g., games and product demos), and the like. Messages may be communicated via printed media, through receivers such as television sets and radios, or via personal computing devices such as laptops, tablets, smartphones, wearables and other such computing devices.
A message may be sent and received via more than one communications channel. For example, a message informing the users of a networked computing service of a security breach, and advising them to change their passwords, may be sent via email, a banner on a support website, a blog post, and a news article. As a further example, a consumer may hear a product advertisement on the radio, receive a sponsored listing for the same product in search results, and see a video clip of the product on a social network. However, some of these channels may have little to no influence on the behavior of the recipient, while other channels may have a more significant effect.